Compound detonators



Patented Feb. 18, 1947 UNITED STATES Area-r oFFIcE No E rawing. Application November 11, 1936, Serial No. 110,356

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 8 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

The subject of this invention is a detonator and the invention refers more particularly to detonators for use in ammunition.

Heretofore it has been customary to load detonators intended for use in ammunition designed for military use With mercury fulminate. EX- perience has shown that detonators so loaded deteriorate when placed in storage 50 that replacement is necessary at certain intervalsof time depending upon the temperature at which the ammunition has been stored.

For the purpose of overcoming this disadvantage it is proposed to use lead azide either alone or in combination with nitro compounds for instance trinitrophenylmethyl-nitramine; trinitrotoluol; tetranitroanilin, etc.

By reason of the comparative insensitiveness of such a main charge to the impact of the firing pin it is necessary to make the detonator a compound one in which the main charge is arranged with a cover or igniter charge which is more sensitive to the impact of a firing pin and which will detonate the main charge of the detonator. This cover charge is composed of antimony sulphide, potassium chlorate and lead azide.

The compound detonator contains a secondary charge of a nitro compound such as tetryl, trinitrotoluol etc., a primary charge of lead azide, and an igniting charge or cover charge as h tofore set forth.

The igniting charge may contain an equal percentage of each of the ingredients or they may vary from 23 to 43 percent. Abrasive such as carborundum or glass, may be used with this mixture the proportion being approximately 5%, this amount being substituted for a like amount of lead azide.

In loading the detonator the cover or igniting charge is loaded first, the lead azide is then loaded and the nitro-compound is loaded last. The weight of each separate component is controlled by the diameter of the detonator. In a detonator casing having an internal diameter of .190 inch and a length of .34 inch, the igniter charge weighs 60 milligrams, the lead azide charge 190 milligrams, and the nitro compound 80 milligrams. These weights may vary as much as milligrams plus or minus. Stated in another mannor, the igniter charge should have a thickness of inch, he lead azide a thickness of .175 inch and the balance the main charge of a nitro compound. It is to be understood that these thicknesses of charges may be varied as much as 25 percent plus or minus. Since the internal diameter of the detonator and the weight of each of the three layers are given the weight per square inch of each layer can be calculated. By making this calculation, taking into account the plus or minus variation of 10 milligrams, it will be seen that the igniter layer may vary from.

1764 to 24.69 milligrams per square inch, the lead azide layer from 6349 to 7054 milligrams persquare inch, and the nitro compound layer from. 2469 to 3174-. milligrams per square inch.

We claim:

1. A compound detonator comprising a main charge of a nitro-compound, a priming charge of lead azide, and an igniter charge consisting of antimony sulphide, potassium chlorate and lead azide.

2. A compound detonator comprising a main charge of lead azide, and an igniter charge consisting of antimony sulphide, potassium chlorate and lead azide in equal percentages.

3. A compound detonator comprisin a main charge of a nitro-compouncl, a priming charge of lead azide, and an igniter charge consisting of antimony sulphide 23 to 43 percent, potassium chlorate 23 to 43 percent and lead azide 23 to 43 percent.

4. A compound detonator comprising a main charge of a nitro-compound, e, priming charge of lead azide, and an igniter charge consisting of antimony sulphide, potassium chlorate, lead azide and an abrasive.

5. A compound detonator comprising a main charge of a nitro-compound, a priming charge of lead azide, and an igniter charge consisting of antimony sulphide 33 percent, potassium chlorate 33 /3 percent, lead azide approximately 28 percent and an abrasive approximately 5 percent.

6. A compound detonator comprising a main charge of a nitro-compound, a priming charge of lead azide, and an igniter charge consisting of antimony sulphide, potassium chlorate, and lead azide, the ratio of the heights of said charges for a constant diameter column being respectively .115, .175, and .050 plus or minus twenty-five per cent.

7. A compound detonator comprising a main charge of a nitro-compound -90 parts by weight, a priming charge of lead azide -200 parts by weight and an igniter charge of antimony sulphide, potassium chlorate and lead azide 50-70 parts by weight.

8. A compound detonator comprising a main 3 charge of nitrocompound, a priming charge layer of lead azide of 6349 to 7054 milligrams per square inch of layer and an igniter charge layer of antimony sulphide, potassium chlorate, and lead azide of 1764 to 2469 milligrams per square inch of layer.

CLARENCE J. BAIN. LEROY R. CARL.

REFERENCES CITED The following references are of record in the file of this patent:

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